scholarly journals Optimization and Experiment of Mass Compensation Strategy for Built-In Mechanical On-Line Dynamic Balancing System

2020 ◽  
Vol 10 (4) ◽  
pp. 1464
Author(s):  
Zhan Wang ◽  
Bo Zhang ◽  
Ke Zhang ◽  
Guodong Yue

In order to solve the problem of low precision and efficiency in the balancing process due to the movement of balance counterweights in a built-in mechanical on-line dynamic balance system, an optimization strategy for the mass compensation of the mechanical on-line dynamic balancing system is proposed, and a mass compensation optimization model is established. The optimization model takes the phase of counterweight movement as the optimization variable and the residual stress under dynamic balance as the optimization objective. Through the optimization model, the movement phase of the counterweight can be calculated, and the counterweight can be moved to a balanced position that significantly reduces the degree of unbalance. An experiment platform was built to carry out comparison experiments under different rotating speeds and unbalance levels. By comparing the residual stress, amplitude, and dynamic balancing time of the spindle before and after the balance, the accuracy of the phase of the counterweight that is calculated by the optimization model is verified. The optimized dynamic balance compensation strategy and the unoptimized were compared by experiments at different rotating speeds. The experimental results showed that, compared to the unoptimized balance, the amplitude of the spindle after optimizing balance with a dynamic balancing device can decrease by 30.39% on average, with its maximum amplitude decreasing by up 50.18%, and the balancing time can decrease by 31.72% on average, with its maximum balancing time decreasing by up to 43.86%. The research results showed that an optimization strategy can effectively improve dynamic balance efficiency and greatly reduce vibration amplitude, which provides the necessary theoretical basis for improving the running precision of the spindle system.

2014 ◽  
Vol 945-949 ◽  
pp. 777-780
Author(s):  
Tao Liu ◽  
Yong Xu ◽  
Bo Yuan Mao

Firstly, according to the structure characteristics of precision centrifuge, the mathematical model of its dynamic balancing system was set up, and the dynamic balancing scheme of double test surfaces, double emendation surfaces were established. Then the dynamic balance system controller of precision centrifuge was designed. Simulation results show that the controller designed can completely meet the requirements of precision centrifuge dynamic balance control system.


2022 ◽  
pp. 026461962110673
Author(s):  
Yousof Moghadas Tabrizi ◽  
Mohammad Hani Mansori ◽  
Mohammad Karimizadeh Ardakani

The aim of this study was to compare the effect and durability of perturbation and vestibular exercises on balance and the risk of falling in people with visual impairment (VI). Thirty-six men with VI were divided into three groups, including a control and two experimental (perturbation and vestibular) groups. The experimental groups performed perturbation and vestibular exercises for 4 weeks and three sessions per week. Biodex balance system was used to assess balance and falling risk before and after training interventions. To evaluate the effects within and between groups at three levels of measurement: pre-test, post-test, and durability effect between three groups, repeated measures analysis of variance (ANOVA) and one-way ANOVA were used. Repeated measures ANOVA test showed that both experimental groups showed significant improvements in static balance, dynamic balance, and falling risk. In comparison between the groups, the results showed that in the post-test and durability stages, there was a significant difference between the groups and the perturbation exercise group had a greater effect on the dependent variables. Due to the effectiveness of exercises, it is recommended that people with VI pay attention to balance-based perturbation exercises to strengthen the somatosensory system and vestibular exercises to strengthen the vestibular system.


2013 ◽  
Vol 427-429 ◽  
pp. 137-141
Author(s):  
Zhi Jun Sun ◽  
Yang Xu ◽  
Shuang Huang ◽  
Yi Ze Sun

Simulation studies were carried out on the shaft of carpet tufting machine to establish multi-parameter dynamic balancing equations based on Matlab. Through the analysis and comparison of reaction forces between link and spindle before and after dynamic balancing, the optimal parameter solution was acquired under the ideal state. According to the actual situation in the project, the optimum value was obtained by modifying some parameters, which not only made mechanism achieve a better balancing, but also enhanced the transmission of motion performance and improved the operating environment of spindle system.


2014 ◽  
Vol 29 (8) ◽  
pp. 741-751 ◽  
Author(s):  
Andresa R Marinho-Buzelli ◽  
Alison M Bonnyman ◽  
Mary C Verrier

Objective:To summarize evidence on the effects of aquatic therapy on mobility in individuals with neurological diseases.Data sources:MEDLINE, EMBASE, PsycInfo, CENTRAL, CINAHL, SPORTDiscus, PEDro, PsycBITE and OT Seeker were searched from inception to 15 September 2014. Hand-searching of reference lists was performed in the selected studies.Review methods:The search included randomized controlled trials and quasi-experimental studies that investigated the use of aquatic therapy and its effect on mobility of adults with neurological diseases. One reviewer screened titles and abstracts of retrieved studies from the search strategy. Two reviewers independently examined the full texts and conducted the study selection, data extraction and quality assessment. A narrative synthesis of data was applied to summarize information from included studies. The Downs and Black Scale was used to assess methodological quality.Results:A total of 116 articles were obtained for full text eligibility. Twenty studies met the specified inclusion criteria: four Randomized Controlled Trials (RCTs), four non-randomized studies and 12 before-and-after tests. Two RCTs (30 patients with stroke in the aquatic therapy groups), three non-randomized studies and three before-and-after studies showed “fair” evidence that aquatic therapy increases dynamic balance in participants with some neurological disorders. One RCT (seven patients with stroke in the aquatic therapy group) and two before-and-after tests (20 patients with multiple sclerosis) demonstrated “fair” evidence on improvement of gait speed after aquatic therapy.Conclusion:Our synthesis showed “fair” evidence supporting the use of aquatic therapy to improve dynamic balance and gait speed in adults with certain neurological conditions.


2019 ◽  
Vol 8 (5) ◽  
pp. 179
Author(s):  
Ömer Özer

Maximal strength, muscular endurance, maximal aerobic power, and anaerobic capabilities, power are needed to have victory for wrestlers in a wrestling competition.The aim of the study is to investigate the effect of acute muscular fatigue on static and dynamic balance performances in elite wrestlers. Ten elite male wrestlers (25 ± 2.3 years, 181 ± 6.5 cm, 84 ± 4.2 kg) participated in the study voluntarily. Participants were undertaken dynamic and static balance test before fatigue exercise (in Cybex) and immediately after fatigue exercise, theywere undertaken dynamic and static balance test again. SPSS packet program was used to evaluate the data. There were no statistically significant differences in static and dynamic balance before and after fatigue. The results show that wrestlers’ balance is not affected by muscular fatigue, so there is no need for balance exercise after fatigue at least according to this study.


2019 ◽  
Vol 16 (3) ◽  
pp. 807-814
Author(s):  
Hilal Kılınç ◽  
Hacı Bayram Temur ◽  
Hacalet Mollaoğulları

Bu çalışma 8-10 yaş arası erkek çocuklarda yüzme egzersiz ve bosu çalışmalarının dinamik dengeye etkisini incelemek amacıyla yapıldı. Yaşları ortalaması 8,9333±,78492 yıl olan 30 katılımcı veli ve antrenörlerinden gönüllü katılımları ile ilgili aydınlanmış̧ onamları alınarak çalışmaya dahil edildi. Bunların 20' si egzersiz grubu diğer 10'u da kontrol grubudur. Egzersiz grubunun en az 1 yıl yüzme eğitimi almış olmalarına ve haftada 3 gün düzenli olarak yüzme antrenmanı yapıyor olmalarına dikkat edildi. Egzersiz grubu rastgele yöntemle 2 gruba ayrıldı. Birinci gruba yüzme ve bosu çalışmaları, ikinci gruba ise sadece yüzme egzersizleri yaptırıldı. Bu çalışma 10 hafta süreyle uygulandı. Katılımcıların antropometrik ölçümler ile dinamik denge ölçümleri planlanan antrenman programı öncesi ve sonrası olmak üzere iki defa alındı. Çalışma Van Olimpik yüzme havuzunda uygulandı. Verilerin analizinde SPSS 21 paket programı kullanıldı.  Analizler sonucunda yüzme eğitimi alan grubun A (Anterior), PM (Posteromedial) ve PL (Posterolateral) ön test - son test ölçüm  değerleri arasında anlamlı (p<0,01) fark olduğu saptandı. Yine yüzme ve bosu eğitimi alan grubun PM ve PL ön test - son test ölçüm  değerleri arasında anlamlı (p<0,01) fark olduğu belirlendi. Seçilmiş değişkenlerin ön test- son test ölçüm değerleri arasındaki farkların gruplar arasında anlamlı (p<0,05)  bir farklılığın olmadığı görüldü.   ​Extended English summary is in the end of Full Text PDF (TURKISH) file.   Özet This study was carried out to investigate the effect of swimming exercise and bosu studies on dynamic equilibrium in 8-10 years old boys. They were included in the study by taking their enlightened consent about their voluntary participation from 30 participants parents and coaches with an average age of 8,9333 ±, 78492 years. 20 of them were exercise group and 10 of them were control group. The exercise group had at least 1 year of swimming training and swimming training 3 days a week was paid attention to be doing regularly. The exercise group was randomly divided into two groups. The first group had swimming and bosu exercises and the second group had only swimming exercises. This study was performed for 10 weeks. The participants' anthropometric measurements and dynamic balance measurements were taken twice before and after the planned training program. The work was carried out at the Olympic swimming pool in Van. SPSS 21 package program was used to analyze the data. As a result of the analyzes, it was found that there was a significant difference (p<0.01) between the A (Anterior), PM (Poateromedial) and PL (Poaterolateral) pre-test and post-test measurements of the swimming group. It was determined that there was a significant difference (p <0.01) between the PM and PL pretest - posttest measurements of the group receiving swimming and bosu training. There was no significant difference (p <0.05) between the pre-test and post-test values ​​of the selected variables.


2017 ◽  
Vol 168 (1) ◽  
pp. 68-72
Author(s):  
Piotr BOGUŚ ◽  
Mateusz CIESZYŃSKI ◽  
Jerzy MERKISZ

The paper presents a method of classification of locomotive Diesel engine states basing on vibration signals taken from an engine body and using chosen statistical parameters calculated for the original signal and it wavelet multiresolution components. The researches presented in the paper concern estimation of an engine states before and after a general repair. The target application of the presented researches is an on-line diagnostic system which can complement standard OBD systems. To this purpose the applied methods should not base on complex analysis of some spectral, time-frequency or scalogram plots but rather on choosing single diagnostic parameters which are suitable for the fast on-line diagnostic. The results have showed the significant difference in distinguishing of engine work before and after a general repair using some chosen statistical parameters applied to vibration signals.


EAD em FOCO ◽  
2016 ◽  
Vol 6 (2) ◽  
Author(s):  
Fernanda Roda Cassundé ◽  
Edson Gomes Silva ◽  
Laís da Silva Santos ◽  
Adler Henrique Santos Souza ◽  
Graça Suely Gomes Souza ◽  
...  

O presente trabalho tem como objetivo avaliar as expectativas e experiências dos estudantes em relação à disciplina O Estado e os problemas contemporâneos, do Curso de Especialização em Gestão Pública da Universidade Federal do Vale do São Francisco (Univasf). Para isso, foi realizada a aplicação do questionário de autoavaliação Colles (Constructivist Online Learning Environment Survey) verificando-se as possíveis mudanças na percepção e comparando-se os resultados do antes e do depois referente a seis dimensões: relevância, reflexão, interação, apoio dos tutores, apoio dos colegas e compreensão. Participaram da pesquisa 97 alunos, em dois momentos diferentes: no início das aulas, para conhecer as expectativas dos estudantes e no final delas, para se ter uma compreensão da realidade vivenciada. Os resultados revelaram que a análise da experiência sempre foi inferior quando comparada à análise da expectativa em todos os aspectos apresentados, evidenciando que alguns participantes sentenciaram não ter alcançado os objetivos pretendidos.Palavras-chave: Colles, Educação a distância, Avaliação, Pós-graduação, PNAP.  Social Constructivist Evaluation of an Experience in Distance Education: the use of Colles as Data Collection InstrumentAbstract This study aims to evaluate the students expectations and experiences regarding the subject "The State and the contemporary problems", in Public Management post-graduation from the Federal University of São Francisco Valley (UNIVASF). For this, the application carried out the self-assessment questionnaire COLLES (Constructivist On-line Learning Environment Survey) checking for possible changes in perception and comparing the results before and after referring to the six dimensions: relevance, reflection, interaction, support tutors, peer support and understanding. The participants were 97 students in two different times at the beginning of classes, to meet the expectations of students and at the end of these, to have an understanding of experienced reality. The results showed that the students' experience overcame the negative assessment in all aspects presented, showing that some participants sentenced not have achieved the intended objectives.Keywords: COLLES, Distance education, Evaluation, Postgraduate studies, PNAP. 


Author(s):  
Kristina Zaičenkovienė ◽  
Renata Rakovaitė

Research background. Falling is one of the most important problems in the elderly’s mobility disorder, which is most often affected by the loss of balance. It is known that Pilates exercises could help to increase the deep muscle strength, improve posture and proprioception, which affects the improvement of the balance. Objective – to evaluate the effects of Pilates exercises on the elderly’s static and dynamic balance. Methodology. The study population consisted of 20 volunteers, men and women, who were divided into Pilates exercises (n = 10, age 65.1 ± 2.6) and control (n = 10, age 68.6 ± 4.9) groups. The study group participated in Pilates classes 2 times per week for six weeks (session duration 60 minutes). The control group did not participate in any physical activity, but they were physically active as usually in their daily life. The main outcome measures were assessed before and after the intervention. The static balance was assessed by measuring posturographic parameters using the force platform, dynamic balance was measured with the Timed up and Go Test (TUG) and the Four Square Step Test (FSST). Results. The results showed signifcant improvement in static balance of the experimental group after the Pilates exercises during standing tests when the feet were apart, eyes opened and closed and when the feet together with eyes opened, and when the foot was in front of the other foot. The results of the control group did not differ during both tests. The results of both groups did not differ in the static balance tests before and after the study, but after the Pilates exercises, the results of the Pilates group signifcantly differed from the control group test results when the feet were in shoulder line with open eyes. The results of the dynamic balance after Pilates exercises signifcantly improved in both tests in the study group. Before the study, there were not statistically signifcant differences in the dynamic balance results between the groups. Conclusions. Six-week Pilates exercises had a positive effect on the elderly’s static and dynamic balance.Keywords: Pilates training, static balance, dynamic balance.


1986 ◽  
Vol 108 (3) ◽  
pp. 285-291
Author(s):  
M. S. King ◽  
J. K. Blundell

Industrial robots in use today lack the total ability to perceive and interact with their environment. This limitation is a major obstacle confronting robotic systems developers. This work outlines an on-line process optimization strategy which allows a robot to work within a time-varying environment. After developing the kinematic model of the robot and its relationship to its environment, the process optimization strategy is simulated. The performance of the system is measured by using an index of performance and comparing the simulation results against a series of non-optimized models. The results indicate that on-line process optimization strategy significantly increases the performance of a robotic system operating in a time-varying environment.


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